论文标题
眼镜中的玻色峰振动模式具有杂交语音和准定位激发
Boson-peak vibrational modes in glasses feature hybridized phononic and quasilocalized excitations
论文作者
论文摘要
结构眼镜和其他无序固体的标志是，在Debye Spectrum Spectrum $ d _ {\ rm debye}（ω）$（$ω$）（$ω$表示振动频率）上的出现，在汉密尔顿（Hamiltonian）是汉密尔顿（Hamiltonian Is Translation in Translation Anvariation in translistation Brovational Invartiation intranciate Invariant）中。这些多余的振动 - 其签名是状态降低的密度$ d（ω）/d _ {\ rm debye}（ω）$的THZ峰，称为波森峰 - 几十年来已经抗拒了完整的理论理解。在这里，我们提供了直接的数值证据，表明玻色子峰附近的振动由带有许多准定位激发的声子组成，最近显示后者通常会填充从熔体和无序晶体中淬灭结构玻璃的振动镜头的低频尾巴。我们的结果表明，在玻色峰频率的附近存在和附近存在准化激发，因此构成了玻璃中过量振动模式的基本构建块。
A hallmark of structural glasses and other disordered solids is the emergence of excess low-frequency vibrations, on top of the Debye spectrum $D_{\rm Debye}(ω)$ of phonons ($ω$ denotes the vibrational frequency), which exist in any solid whose Hamiltonian is translationally invariant. These excess vibrations -- a signature of which is a THz peak in the reduced density of states $D(ω)/D_{\rm Debye}(ω)$, known as the boson peak -- have resisted a complete theoretical understanding for decades. Here, we provide direct numerical evidence that vibrations near the boson peak consist of hybridizations of phonons with many quasilocalized excitations, the latter were recently shown to generically populate the low-frequency tail of the vibrational spectra of structural glasses quenched from a melt and of disordered crystals. Our results suggest that quasilocalized excitations exist up to and in the vicinity of the boson-peak frequency, and hence constitute fundamental building blocks of the excess vibrational modes in glasses.
